Furnace resistor mounting



Patented Jan. 12, 1926.'

entran srirrss ATENT FFlCE,

ALVIN D. KEENE, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION 0F PENNSYLVANIA.

F'URNACE RESSTOR MOUNTING.

Application filed November 20, 1923.

T0 all fwliom it may concern:

Be it known that l, ALVIN D. KEENE, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Furnace Resistor Mountings, of which thefollowing is a specification.

My invention relates to electric furnaces and particularly to resistor mountings for electric furnaces.

The object of my invention is to provide a relatively simple mounting for a high-capacity resistor that shall permit of being easily placed in, and removed from, the furnace structure.

In my copending application, Serial No. 658,032, tiled August 18, 1923, and assigned to the lVestinghouse Electric & Manufacturing Company, l have illustrated a resistor mounting for an electric furnace comprising a single-layer resistor member.

The present invention relates to means for providing a double-layer resist-or in order that a relatively large amount of electric energy may be translated into heat over a given unit of area of the walls of a furnace l chamber without increasing the amount of energy per unit of area of the resistor itself to a relatively high value.

ln practicing my invention, l provide a plurality of refractory heat-insulating Walls ciu-losing a furnace chamber and each supportingv a plurality of spaced sets oll refractory members, of substantially Tshape, projecting into the? furnace chamber. 'lhe refractory members of T-shape are spaced apart a suitable distance in each set and cach member is provided with a laterallyvextending groove in that part of its length located within the furnace chamber.

Pairs of relatively narrow and thin refractory plates, having laterally extending grooves in their inner surface, are held by pairs of members of T-shape closely adjacent to the Wall. The length 0f the relatively narrow bars is in such relation to the distance between the spaced pairs of refractory members of T-shape, that-they may be placed in their' proper operative positions by a lateral and tilting motion thereof relatively to the adjacent wall of the furnace.

y A relatively heavy resistor member preformed to comprise a plurality of straight,

Serial No. 675,863.

substantially parallel-extending and end connected convolutions, is held by the grooved plates whereby the convolutions extend subv stantially parallel to the furnace walls and closely adjacent thereto in two parallel spaced planes. The resistor members are substantially self-supporting lbetween the refractory, grooved supporting bars.

ln the single sheet of drawings,

liigure 1 is a view, in vertical lateral scction, of an electric furnace embodying my invention, f

Fig. 2 is a view, partially in lateral section and partially in end elevation, of a part of an electric furnace comprising the device embodying my invention, and

Fig. 3 is a view, in front elevation of the parts illustrated in F ig. 2.

An electric furnace 11 comprises side and end walls 12, a bottom wall 13, and a top wall 14, each of which is constituted by a plurality of bricks `or blocks of a suitable refractory heat-insulating material.

An inner lining 15 for each of the walls of the furnace structure may comprise a plurality of bricks or blocks of suitable refractory high-temperature resisting mate-- rial, the hereinbefore described walls being suitably spaced apart vto provide a furnace chamber 16 of any suitable or desired contour and dimensions. l

ln building up the inner layers l5, a plurality of sets of elongated refractory sup porting members 17, of substantially T- shape, are located therein syn'imetrically spaced, both laterally and longitudinally of the supporting wall. Each of the members 17 extends a short distance into the furnace chamber 16 and is provided with a laterally extendin groove 18 in its lower surface. The dept of the groove or depression 18 is somewhat greater than that which is formed by the integral upper part of a laterallyextending flange 19 of the member 17. The groove or depression 18 is of substantially the Same extent, longitudinally of the members 17, as the distance that they project into the furnace.

Pairs of relatively narrow and thin refractory bars 21 are located between adjacent spaced pairs of members 17 in substantially the position illustrated in Fig. 2 of thol drawing. Each of the members 21 is provided with a plurality of laterally extending grooves 22, the location of the grooves in the two bars 21 being such that the grooves in one bar are located in staggered relation relatively to the grooves in the other bar.

The bars 21 may be moved into their proper operative positions substantrally as shown in Figs. 2 and 3 of the drawing in either one of two ways, First,`they may be moved into position by a movement laterally of' the members 17 and substantially parallel to the face of the adjacent furnace wall or, second, they may be moved into position by a lateral and tilting movement thereof in a direction substantially at right angles to the plane of the adjacent furnace wall. In the latter case, the upper end of cach bar may be placed in the groove 18 and pushed up* Wardly until its upper end engages the member 17. This 'position will permit of the lower end clearing the upper edge of the flange 19 and the bar 21 may then be moved into its proper operative position by a tilting movement thereof toward the adjacent furnace wall.

Each of the bars 21 has extending through its grooves 22 a resistor member 23 comprising a relatively heavy rod or wire preformed to comprise a plurality of straight and substantially paraIleLeXtending, end connected convolutions substantially of the form illustrated in Fig. 1 of the drawing.

ln installing the respective resistor members 23, the inner one, viz, that immediately adjacent to the furnace wall may be held in substantially its proper operative position and the spaced sets or pairs of inner bars 21 placed in their proper operative positions, as was hereinbefore described. Then the outer or second resistor member 23 may be held against the outer surfaces of the two spaced bars 21, and the. outer sets of horizontally spaced bars 21 may be laced in their proper operative positions which will mount the two resistor members in substantially the positions illustrated in the drawings.

The grooves in the bars 21 may be located unsymmetrically with regard to the ends thereof and if the pairs of bars 2l extending between the two vertically spaced members 17 are so located that one is inverted relatively to the other, the individual convolutions ofthe two resistor members 23 will be located in staggered relation relatively to each other, substantially asillustrated in Fig. 1 of the drawings. This location-insures that the outer resistor member 23 will not cover the inner resistor member 23 and that the heat generated by the inner resistor member will have a free and unobstructed path into the chamber and to any material that may be located therein.

As the resistor members 23 will expand and contract'during the operation of the furnace, particularly when being heated or l cooled, it is desirable that the bars 21 be prevented from any lateral movement relatively to the members 17.

I may employ keys 24, of,substantially L-shape, that tit into openings in the members 17, the two openings being suitably spaced apart so that the keys 24 will be located closely adjacent to, and on each side of, the bars 21. If desired, I may employ longitudinally extending grooves, in the members 17 back of the flanges 19, in which case, the side walls of these grooves will operate as means to prevent movement of the bars 21 laterally of the members 17.

The resistor members 23 may comprise a plurality of individual wires that may be connected by any suitable or desired means, or, as is shown more particularly in Fig. 1, the entire group of resistors mounted adjacent to a furnace wall may comprise a slngle length of resistor wire.

I prefer to bend the end portions -of the resistors 23 at substantially right angles to the plane of the convolutions in order to ermitof placing thel resistor members in t eir proper operative positions by a movement of the resistor units at substantiall right angles to the plane of the convo utions. This movement permits of inserting the end portions of the resistor members through suitable openings 25, provided for this purpose in the furnace walls.

In the above mentioned copending a plication, a heating element of only one ayer is disclosed, and if it is desired to obtain a relatively large 'amount of energy per unit area, of wall surface, it is necessary to operate the resistor at a relatively high temperature and with a relatively large amount of energy input. The constructlon herein disclosed provides, however, a double layer winding that permits of operating each individual resistor member at a relatively low energy input while still providing a relatively large energy translated into heat per unit area of wall surface.

This construction, therefore, is effective to prolong the life of the resistor member or to permit of its ,being operated safely at higher temperatures than has been the case heretofore, where only a single layer winding was employed.

Various moc ifcations and changes may be made without departing from the spirit and scope of the invention, and I desire therefore, that only such limitations shall be placed thereon as are imposed by the prior art or are set forth in the appended claims.

I claim as my invention:

1. In an electric furnace, in combination, a. plurality of spaced sets of fixed, alined and spaced members, of substantially T-shape,

airs of superposed coextensive substantialy vertcally-extending, relatively narrow, supporting bars having laterally-extending grooves in one surface thereof spported by neoaavc said members of '1F-shape, and pairs of relatively heavy preformed resistor members extending through said lateral grooves in the alined supporting-bars and therebetween, said resistor members being located in adjacent parallel planes.

2, ln an electric furnace having a plurality of refractory Walls enclosing a turnace chamber, in combination, a. pair of extended resistor members located in spaced parallel planes and each comprising a plurality of integral, end-connected, and substantially 1 parallel-extending straight convolutions, pairs of grooved relatively narrow refractory bars for supporting said resistor menibers` the pairs of said bars being' located in superposed position, and pairs of verticallyspaced refractory membersmounted in fixed positions in one of said vvalls and having lateral grooves in opposing faces to receive the ends of said y airs'of refractory bars to support and hol the same.

3.` ln an electric furnace having a plurality of refractory Walls enclosing a. 'furnace chamber, in combination, a. pair of extended resistor members located in spaced parallel planes and each comprising a plurality of integral, end-connected, and sub-y stantially parallel-extending straight convolutions, pairs of groove'd relatively narrow refractory bars for supporting said resistor members, the pairs of said bars being located in su' erposed position, pairs of verticallyspace refractory members mounted in fixed ositions .in one of said walls and having ateral grooves in opposing faces to receive the ends of said pairs ci refractory bars to support and hold the same, and means operatively engaging said refractory members to prevent movement of said bars laterally of said refractory members.

4. In an electric furnace lia-ving,r a. plurality oi refractory Walls enclosing a -`inrnace chamber, in combination, a pair of eX- tended resistor members located in spaced parallel planes and each comprisinga plurality of integral, end-connected, and substantially paraHel-extending straight convolutions, pairs of grooved relatively narrow refractory bars for supporting said resistor members, the pairs of said bars being located in snperposed position, and pairs of vertically-spaced refractory members mounted in lined positions in one of said vvalls and having lateral grooves in opposing forces to receive the ends of said pairs of refractory bars to support and hold the Same, the groove in the upper lace beingr shalloiver than the groove in the lower face and the bars being placed in their proper operative positions by a lateral and tilting movement thereof relatively to said refractory members,

5. In an electric furnace, in combination, a plurality of refractory Walls enclosing a furnace chamber, a plurality of spaced sets of alined refractory members lixedly supported by one of said Walls and having lateral grooves in the sides adjacent the end projecting into the furnace chamber, and pairs oi' superposed and coextensive. refractory, resistor supporting bars extending between pairs/of alined refractory members, said bars being placed in their proper operative positions rela tively to said refractory members by a tilting and lateral movement thereof relatively to the adjacent furnace Wall, and a pair of extended resistor members comprising a plurality of substantially parallel extending straight con-volutions supported in parallel, spaced relation by spaced bars, the convolutions ci' one resistorbeing staggered relatively to the convolutions of the other resistor.

In testimony whereof, l have hereunto subscribed my naine this llth day of Novembei', i923, Y ALVIN D. KEENE. 

